Correctable graphic system

ABSTRACT

A correctable graphic system which will permit easy correction of written material by the application of a correcting fluid of dilute aqueous ammonia solution comprising: a paper base, a rubber latex or acrylic emulsion barrier coating which is insoluble in the correcting fluid and relatively resistant to the penetration of ink and a proteinaceous ink receptive surface coating which is soluble in the correcting fluid.

Unite States atent Smith et a1.

[15] 3,655,427 [451 Apr. 11, 1972 154] CORCTABLE GRAPHIC SYSTEM [72]Inventors: Walter J. Smith, Arlington; John W. Rafferty, Marblehead,both of Mass.

[73] Assignee: The Parker Pen Company, Janesville, Wis.

[22] Filed: Oct. 28, 1969 211 App1.No.: 871,971

[52] US. Cl ..ll7/76 P, 117/2 R, 117/2 TC, 117/15, 117/80,117/83,1l7/l02R [51] Int. Cl. ...B32b 25/06, B44d/14, B44d 5/04 [58]Field ofSearch ..l17/2 R,2TC, 76 P, 80, 83, 117/15, 102 R [56]References Cited UNITED STATES PATENTS 5/1938 Elliot ..ll7/76P 11/1958l-loeletal ..117/83X 2,955,970 10/1960 Rice et a1. ..l17/83 X 3,076,7202/1963 Rice et a1 ....1 17/83 X 3,086,884 4/1963 Betschmann ....1 17/76P 3,468,698 9/1969 Pelletier et a1..... ....1 l7/76 P 3,494,783 2/1970Kimura et a1. ..1 17/76 P 3,520,242 7/1970 Kemp et a1 ..1 17/76 PXPrimary Examiner-William D. Martin Assistant Examiner-Ralph HusackAtt0rneyBacon & Thomas [57] ABSTRACT 1 Claim, No Drawings CORRECTABLEGRAPHIC SYSTEM DESCRIPTION OF THE INVENTION Despite advances in writinginstruments, inks, etc., the correction of written material is still arelatively imprecise operation usually resulting in a noticeable surfaceblemish. An object of the present invention, therefore, is the provisionof a novel and improved correctable graphic system which will permiteasy correction of written material.

A further object of the present invention is the provision of acorrectable graphic system which is usable with any kind of writinginstrument, ink, etc.

Further objects and improvements of the present invention will beapparent upon reading the undergoing specification and claims.

According to the present invention a correctable graphic system whichwill permit easy correction of written material by the application of acorrecting fluid is provided comprising: a paper base, a resinousbarrier coating which is insoluble in the correcting fluid andrelatively resistant to the penetration of ink and an ink receptivesurface coating which is soluble in the correcting fluid. There are manyadvantages to the novel and improved correctable graphic systemaccording to the present invention. The correctable graphic system isapplicable to every kind of writing method, etc. and no special ink orwriting instrument is required. Only a specially coated paper isrequired and this specially coated paper is producible on standard paperfinishing equipment. Various weights and kinds of paper can be employedsince only the finish is special and, additionally, no dangerous ormessy chemicals are required for correction.

According to the present invention, the written (handwritten,typewritten, etc.) material or line trace remains wholly in the surfacecoating which is removed by the application of a correcting fluid whichis a solvent for the surface coating. Since the surface coating is onethat can be readily dissolved, any part of the written material or linetrace can be removed at will.

The base of the correctable graphic system may be an ordinary writing ortypewriting paper base. It has been found necessary to provide a barriercoating overlying the paper base so that dissolved surface coating anddispersed trace line color will not strike through to the paper base.The barrier coating, therefore, must be relatively resistant to thepenetration of ink (wet inks, ballpoint, typewriter, etc.), correctingfluid and solubilized surface film into the paper base. The barriercoating also serves as a support for the surface coating and should holdthe surface coating away from the paper base. To accomplish this, thebarrier coating must lie on the paper surface as a tight film.Latex-type resinous binders do this very well. Both rubber latices andacrylic emulsions have been employed with success. The coating weightand thickness of the barrier coating is conventional.

Overlying the barrier coating is a surface coating which is inkreceptive and is adapted to receive the writing or line trace. Thesurface coating is the means of erasing any unwanted mark and isselectively removable. It is soluble in the correcting fluid and may bemade using any of the many soluble binders. Proteinaceous coatings arepreferred and as a practical matter casein works very well since itresists water wetting and is easily removed by the addition of diluteammonia solution. Moreover, casein is a standard paper-coating material.The surface coating may be pigmented, for example, with clay andtitanium dioxide. To the greatest extent consistent with its principlefunction, the barrier coating should be pigmented to match the surfacecoating or, in other words, the surface and barrier coatings should bepigmented alike so that removal of the surface coating does not resultin a too noticeable surface blemish. The coating weight and thickness ofthe surface coating is conventional.

The correctable graphic system according to the present invention may beeasily written upon using any writing instrument and ink (wet inks,ballpoint, typewriter, etc.). When an error is made, correction may beeasily affected by touching the error spot with a correcting fluid inwhich the surface coating is soluble and the barrier coating isinsoluble. The desired spot is then blotted away and the area allowed todry. The correction may be made on the remaining surface. In the case ofa casein surface coating, a dilute water solution of ammonia may beemployed as the correcting fiuid and an acrylic resin as the barriercoating.

The following non-limitative example illustrates the invention:

EXAMPLE Ten (10) parts of water were added to a dry mix of 2 parts ofTitanox (TiO and 18 parts of Ultraglos (clay) and the mixture was workedto a smooth paste. A solution of 20 parts water and 0.2 part oxalic acidwas added to the paste while thoroughly mixing. Sixteen (16) parts ofRhoplex l-lAl2 (an aqueous dispersion of acrylic polymer available fromRohm & Haas Co.) was then added to the paste with good mixing. Thiscomposition was coated on paper stock using a No. 10 rod, air dried andthen cured for 15 minutes at 300 F. Twelve (12) parts of water wereadded to 4 parts of casein (cold) while stirring to a paste. 0.5 part ofconcentrated ammonium hydroxide (NI-LOH) was added to the casein andwater, stirred and heated for 15 minutes at F. (double boiler) to form asolution. Fifteen (15) parts of water were added to a dry mix formed byadding 3 pans of Titanox (TiO to 27 parts of Ultraglos 90 (clay) withgood stirring until a smooth paste was formed. The casein-water solutionformed above was added to the paste while stirring to a smooth coatingmixture. This mixture was coated on top of the above applied base coatwith a No. 10 rod, air dried and cured for 5 minutes at 130 F. Thesurface coating was readily removable by the application of ammonia.

We claim:

1. A correctable graphic system which will permit easy correction ofwritten material by the application of a correcting fluid of diluteaqueous ammonia solution, said system comprising a paper base, aresinous barrier coating consisting essentially of an acrylic resinwhich is insoluble in said correcting fluid and relatively resistant tothe penetration of ink overlying said base and an ink receptive surfacecoating consisting essentially of casein which is soluble in saidcorrecting fluid overlying said barrier coating, and wherein the surfaceand the barrier coating both contain the same pigment.

